The present invention pertains to a system and method for high throughput sample preparation using column chromatography, followed by analysis of the samples, where the analysis may include mass spectrometry and optical interrogation, such as fluorescence spectrometry, Raman spectroscopy, and UV absorption.
High-throughput screening (HTS) is a method for the rapid and accurate analysis of large numbers of chemical compounds for activity against selected targets. Typical chemical libraries contain hundreds of thousands to millions of separate compounds that are screened against a wide variety of targets. The large numbers of compounds that must be routinely screened has led to a requirement for new technologies capable of rapid and quantitative analysis.
Various types of analysis performed on samples are enhanced by first preparing the sample. In particular, mass spectrometry is a powerful technique uniquely suited for many HTS applications. Mass spectrometry allows accurate quantification of a compound based on its mass alone, eliminating the need for the development of specific spectroscopic assays. The current state-of-the-art mass spectrometers using atmospheric pressure ionization (API) interfaces are not compatible with samples in solutions that contain high levels of non-volatile salts or contaminants. Non-volatiles in the sample can cause both suppression of the desired sample signal and can cause the mass spectrometer to fail due to build-up of precipitates within the ion guide and inlet. Therefore, samples must be purified from non-volatile contaminants and desalted prior to analysis. Additionally, this must be performed, as discussed above, in a manner conducive to high throughput screening.
A system for high throughput sample preparation and analysis using column chromatography is presented. The system includes a plurality of ports, each port having both a port input that interfaces with a first fluid source and a port output. A fluidic circuit is coupled to each port output and to a second fluid source, the fluidic circuit for controlling fluid flow from the plurality of ports and the second fluid source. The fluidic circuit is also coupled to a plurality of chromatography columns. An interface to an analyzer is provided that receives output from at least one of the plurality of chromatography columns. A translation stage allows for movement of the plurality of chromatography columns relative to the analyzer, such that sample output from one of the plurality of chromatography columns can be selectively presented to the analyzer.
In related embodiments of the invention, the system may include a plurality of syringes, each syringe for aspirating a sample to be analyzed and for acting as the first fluid source for one of the plurality of ports. The plurality of syringes may be in fixed positions relative to each other. For example, the plurality of syringes can be positioned in a linear array with 9 millimeter spacing between each of the syringes. The plurality of syringes may interface with the plurality of ports in a parallel manner. The plurality of syringes may be controlled by a controller, the controller comprising at least one device from the group of devices consisting of a robot, a translational stage, and a computer. Each port may include a compression fitting for interfacing with one of the plurality of syringes. The system may include a washing station for cleaning the array of syringes.
In other related embodiments of the invention, the sample to be analyzed may be located on a movable surface. The movable surface may be a fiber, laminate, web, or belt. The first fluid source may include a plurality of tubes, each tube for interfacing with one of the plurality of ports.
In still other related embodiments of the invention, the fluidic circuit includes a plurality of valves, each valve controlling fluid flow from the port output of one of the plurality of ports. A plurality of tee unions are provided, each tee union coupled to one of the plurality of valves and at least one chromatography column. A pump pumps fluid from a second fluid source, and at least one selection valve selectively couples an output from the pump to at least one of the plurality of tee unions. At least one of the plurality of valves may be an actively controlled shutoff valve or a passive check valve.
In yet other related embodiments of the invention, the interface may include a plurality of electrospray ionization sprayer tubes for interfacing with a mass spectrometer; each electrospray ionization sprayer tube coupled to one of the chromatography columns. The plurality of chromatography columns may be in fixed positions relative to each other, and may be positioned in a fixed linear array.
In another embodiment of the invention, a method for high throughput sample preparation and analysis using column chromatography is presented. A plurality of ports is interfaced with a first fluid source, each port having both a port input coupled to the first fluid source and a port output. Fluid flow is controlled from each port output and a second fluid source to a plurality of chromatography columns. The plurality of chromatography columns is moved relative to the analyzer, such that sample output from one of the plurality of chromatography columns can be selectively presented to the analyzer.
In related embodiments of the invention, the method may further include aspirating samples into a plurality of syringes, and interfacing the plurality of syringes with the plurality of ports. The syringes may be controlled using at least one device from the group of devices consisting of a robot, a translational stage, and a computer. The syringes may be cleaned at a washing station prior to aspirating samples.
In a related embodiment of the invention, the control of fluid flow from each port output and a second fluid source to a plurality of chromatography columns includes a plurality of valves that regulate fluid flow from the port output of each of the plurality of valves to a plurality of tee valves, each tee valve being coupled to at least one of the plurality of chromatography columns. Fluid is selectively pumped from the second fluid source to at least one of the plurality of tee valves.
In yet other related embodiments of the invention, the method further includes presenting sample from one of the plurality of chromatography columns to a mass spectrometer using an electrospray ionization sprayer tube. Undesired components may be blocked from entering the mass spectrometer by removing the voltage applied to the electrospray ionization sprayer tube, or by moving the electrospray ionization sprayer tube to a position in which the spray is physically blocked from entering the mass spectrometer.
In still other related embodiments of the invention, the method further includes performing at least one operation from the group of operations consisting of optical interrogation and mass spectrometry. Optical interrogation may include at least one of flouresence spectrometry, Raman spectrometry, and UV absorption. Controlling fluid flow may include delivering samples and wash from one of the plurality of ports to one of the plurality of chromatography columns in one substantially continuous action. Sample output may be selectively presented to the analyzer once every specified time period.